Portable sandblaster

ABSTRACT

Particulate material is dispensed from a portable supply container by application of positive pressure in the open space of the container above the material to fluidize the same, and simultaneously, applying a vacuum through a venturi nozzle. The pressurized fluid for feeding the venturi nozzle and for fluidizing the particulate material preferably originates from a single source, a self-contained propellant tank positioned inside the supply container. An expansion chamber is provided at one end of the venturi nozzle and a dispensing orifice is positioned at the other end. Interconnecting transfer means between the expansion chamber and the open space may be a restricted passage or an open interface; in the latter embodiment a stream splitting lip being formed by said one end of said nozzle. A modified embodiment may be operated in either the upright or inverted position by providing alternative dispensing apertures in the top of the supply container for cooperation with a coupling stopper; sealing and transfer stoppers being positioned to automatically close off the unused aperture and supply pressure to the open space of the container.

United States Patent Harden, Jr.

[ 51 Dec. 5, 1972 [541 PORTABLE SANDBLASTER [72] Inventor: Joseph T.Harden, Jr., Richmond,

[73] Assignee: Creative Ideas, lnc., Richmond, Va.

[22] Filed: July 24, 1970 [21] Appl. No.: 58,093

[52] US. Cl. ..222/4, 222/193, 222/402.l7, 239/308, 239/367, 239/397[51] Int. Cl. ..B05b 7/32 [58] Field of Search ..222/193, 331, 402.17,4; 239/308, 367, 397

[56] References Cited UNITED STATES PATENTS 3,435,600 2/1969 Abplanalp..222/193 3,323 ,686 6/1967 Roth ..222/193 1,881,625 10/1932 Jelliffe etal. ..239/367 X 2,610,433 9/1952 Chisholm et al ..222/193 X 2,675,1474/1954 Odom ..222/193 3,058,669 10/1962 Drell ..239/308 FOREIGN PATENTSOR APPLICATIONS 1,437,550 3/1966 France ..222/308 Primary ExaminerRobertB. Reeves Assistant Examiner-Frederick R. I-Iandren Attorney-Lowe andKing ABSTRACT Particulate material is dispensed from a portable supplycontainer by application of positive pressure in the open space of thecontainer above the material to fluidize the same, and simultaneously,applying a vacuum through a venturi nozzle. The pressurized fluid forfeeding the venturi nozzle and for fluidizing the particulate materialpreferably originates from a single source, a self-contained propellanttank positioned inside the supply container. An expansion chamber isprovided at one end of the venturi nozzle and a dispensing orifice ispositioned at the other end. Interconnecting transfer means between theexpansion chamber and the open space may be a restricted passage or anopen interface; in the latter embodiment a stream splitting lip beingformed by said one end of said nozzle. A modified embodiment may beoperated in either the upright or inverted position by providingalternative dispensing apertures in the top of the supply container forcooperation with a coupling stopper; sealing and transfer stoppers beingpositioned to automatically close off the unused aperture and supplypressure to the open space of the container.

16Claims,7Drawingfigures PATENTED DEC 5 m2 SHEET 2 0F 3 I II II II II IIIII! II 114 PORTABLE SANDBLASTER The present invention relates toportable dispensers and, more particularly, to improvements inself-contained, Aerosol-type dispenser devices for dispensingparticulate material, such as sand and other abrasives.

BACKGROUND OF THE INVENTION In the art pertaining to sandblasting orabrasive cleaning, it is known to dispense the particulate materialthrough a venturi nozzle. This action accelerates the particles to amaximum speed to thereby increase the kinetic energy of the particlesfor maximum release momentum and thus maximum cleaning effect as theparticles bombard the surface being cleaned. The vacuum generated at oradjacent the point of restriction of the nozzle, that is the point oflowest pressure of the nozzle, is utilized to draw the material from thesupply container and into the fast moving stream where the momentum isgained. However, prior to this invention, the dispensing fluid wasrequired to be supplied in large volumes and under great pressure inorder to adequately withdraw the material from the container and projectit with the necessary velocity to obtain a satisfactory cleaning effect.Accordingly, the use of an Aerosol-type or portable dispensing containerfor abrasive cleaning with particulate material and similar operationshas been impractical. Furthermore, a simple dispensing head for quickconversion of an Aerosoltype container to permit inversion of thecontainer to reach hard-to-get places has previously been unavailable.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the presentinvention, a container is provided for holding the supply of theparticulate material with an inner tank holding the Aerosoltypepropellant. A dispensing head is provided on the container and includesan expansion chamber, a venturi nozzle and a dispensing orifice alignedin that order. A supply passage intersects the venturi nozzle at aposition of negative pressure; i.e., point of vacuum, to draw theparticulate material into the fluid stream and thereby dispense the samethrough the dispensing orifice. In accordance with the invention,another passage communicating with the expansion chamber or a point ofhigh pressure, feeds high pressure propellant gas to the interior of thecontainer to fluidize the material and assist in causing the same toflow or be carried through the dip tube and into the venturi nozzle.With this arrangement, it has been found possible to provide asuccessful Aerosol-type Sandblasting or abrading apparatus; whereas,heretofore larger volumes and pressures of the carrier fluid wererequired. Other uses within the broad purview of the invention, includeuse of the device for coating a surface with particulate material or anyother system where the projection of the particles is desired.

Several embodiments of the dispensing head are provided by features ofthe present invention. In one embodiment, the dispensing fluid isprojected into a closed expansion chamber through an intermediateorifice whereby the fluid in a liquid state is permitted to vaporize; aportion of the gas formed then proceeding at high velocity through theventuri nozzle and the other portion being transferred to the supplycontainer to fluidize the material. In another embodiment, the expansionchamber is interconnected with the open space of the supply container byan open interface. The defined stream of fluid from the intermediatepropellant orifice is preferably split by a projecting lip of theventuri nozzle to assure adequate supply of fluid for both fluidizingthe material and operation of the venturi nozzle. A third embodiment ofthe dispensing head assembly includes an integral expansion chamber,venturi nozzle and dispensing orifice pivotally mounted on thecontainer. The assembly is connected at a point spaced from the pivot tothe valve of the propellant container and has an operating thumb leverfor depressing said assembly to cause release of the propellant.

In accordance with another feature of the present invention, adetachable dispensing head assembly is provided to adapt a supplycontainer for operation in either the upright or inverted positions. Inoperation, the supply passage for the material is positioned in a firstaperture in the top of the container having a dip tube so thatconventional upright operation may be obtained. When the container is tobe inverted to operate on hard to reach areas, the supply tube isshifted to an open aperture having no dip tube and thus adapted to feedthe particulate material shifted to the top of the container. Auxiliarystoppers are provided to engage the non-selected aperture and areprovided with transfer passages communicating with the expansion chamberfor pressurizing the corresponding open space within the supplycontainer and thereby fluidizing the particulate material for efficientdispensing. A winged operating plunger is provided to actuate thepropellant dispensing head so as to assure two-hand contact of theoperator; this feature being important especially when utilizing thisembodiment as a large capacity and high propellant power model.

OBJECTIVES OF THE INVENTION Accordingly, it is one object of the presentinvention to provide a portable dispenser for sandblasting or similaroperations having improved operating characteristics to dispense theparticulate material at increased efficiency.

It is another object of the present invention to provide a portabledispenser for particulate material wherein the material is fluidizedwith positive pressure and simultaneously sucked with a vacuum for moreefficient feeding of the material to the dispensing or dischargeorifice.

It is another object of the present invention to provide self-containeddispensing apparatus utilizing negative pressure through the use of aventuri nozzle and fluidizing by positive pressure to feed and dispenseparticulate material at high velocity for cleaning or the like.

It is another object of the present invention to provide a dispensinghead and container combination having mating parts for quick connectionwith either a dip tube or top opening to allow operation in the uprightand inverted positions.

Still other objects and advantages of the present invention will becomereadily apparent to those skilled in this art from the followingdetailed description, wherein I have shown and described only thepreferred embodiments of the invention, simply by way of illustration ofthe best modes contemplated by me of carrying out my invention. As willbe realized, the invention is capable of other and differentembodiments, and its several details are capable of modification invarious obvious respects, all without departing from the invention.Accordingly, the drawings and description are to be regarded asillustrative in nature, and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional viewshowing a first embodiment of the portable dispenser device constructedin accordance with the principles of the present invention;

FIG. 2 is a cross-sectional view of another embodiment of the dispenserdevice of the invention;

FIG. 3 is a cross-sectional view of still another embodiment of thedispenser device constructed in accordance with the principles of thepresent invention;

FIG. 4 is a perspective view from below illustrating a dispenser headassembly of still another embodiment of the invention and adapted forupright or inverted operation in accordance with important features ofthe present invention;

FIG. 5 is a top plan view of a container adapted to mate with thedispensing head assembly of FIG. 4;

FIG. 6 is a cross-sectional view showing the dispensing head andcontainer of FIGS. 4 and 5 in matin g engagement, with the combinationbeing orientated in the inverted position and ready for operation; and

FIG. 7 is a cross-sectional view taken along lines 6- 6 of FIG. 5illustrating the valving system of this embodiment.

DETAILED DESCRIPTION OF THE INVENTION With reference now to FIG. 1 ofthe drawings, a more complete and detailed review of the construction ofa first embodiment of the present invention can be given. A portabledispenser, or as it has come to be known in the trade, an Aerosoldispenser device 10 is provided and comprises an outer container 11holding a supply of particulate material 12 to be dispensed and an innertank 13 holding a supply of propellant 14. The container 11 and tank 13may be of conventional fabrication, such as tin metal, although othermaterials, such as plastics and aluminum, may be utilized if desired.The top and bottom of the container 11 are appropriately sealed at thejoints and around the top of the inner tank 13 so as to provide anairtight sealed structure. Also, the particulate material 12 to bedispensed may be a conventional abrasive, such as silicon oxide or sand,or a specialized abrasive such as silicon carbide or aluminum oxide. Inany case, the material 12 should be dry and sufficiently large inparticle size to be capable of being fluidized, as will be seen later indetail.

It may be desirable to include silica gel capsules 15 or the like toabsorb any moisture in the supply. The propellant 14 may be any of theconventional fluorinated hydrocarbons, sold under the trademark F REONby the Dupont Corporation, Wilmington, Delaware. The specificfluorinated hydrocarbon, dichlordifluoromethane, is particularlysuitable for its high molecular weight and high vapor pressure in thatit affords greater propelling force to the particulate matter, and thushigher dispensing efficiency.

A clip tube 20 is positioned in the inner tank 13 to withdraw thepropellant 14 in a liquid state; a positive vapor pressure existing inthe open space at the top of said tank 13 to force the liquid out. Theliquid is dispensed through a valve 21 having hollow valve element 22;the propellant 14 passing by reason of lateral openings 23 into saidelement 22 when depressed, as shown in FIG. 1. It will be understoodthat when the element 22 is released, spring 24 causes a return of theelement 22 into the top of the valve 21 thereby blocking off theopenings 23.

A propellant dispensing head or cap 27 is provided on top of the element22 for engagement by the hand or finger of the operator. A releasepassageway 28 terminates at an intermediate restricted orifice 29 whichopens into an expansion chamber, generally designated by the referencenumeral 30.

The expansion chamber 30 is a part of a dispensing head assembly 31 andis formed by a tubular housing extension 35 integral with a venturinozzle, generally designated by the reference numeral 36. The nozzle,also a part of the head assembly 31, includes an entrance section 37, arestricted portion 38, and a final expanding section 39, which forms adispensing orifice An interconnecting transfer passage 45 is provided inthe body of the nozzle 36 and communicates through the entrance section37 with the expansion chamber 30 where the propellant has expanded andexists at a relatively high pressure. The other end of the passage 45opens into the open space above the level of particulate material 12, asshown in FIG. 1.

A supply passage 46, also formed in the head assembly 31, communicateswith the restricted portion 38 of the nozzle 36 and thereby is subjectto the lowest pressure of the propellant fluid, due to the well knownBernoullis effect. In short, the effect can be stated as the Equation:

PV+Vzmv =C; 1 wherein it can be seen that for a given volume of fluid,pressure energy (PV) plus kinetic energy (lmv is equal to a constant. Asthe kinetic energy (velocity and thus momentum) increases, it followsthat the pressure must decrease proportional to the velocity squared dueto the volume remaining the same. Thus, the pressure at the mouth of thesupply passage 46 is subatmospheric (a vacuum) and the material 12 inthe passage 46 will be sucked into the flow stream through the nozzle 36and projected through the dispensing orifice 40. The lower end of thesupply passage 46 is connected to a dip tube 47 to permit the supply ofparticulate material 12 to be drawn from the bottom of the container 11.The passage is restricted to assure sufficient fluid passing through thenozzle 36 to generate the desired high velocity and low pressure for theventuri effect. However, the gas passing through the passage 45 into thecontainer 11 is also sufficient to fluidize the material in and adjacentthe end of the dip tube 47 and, as will presently be seen, thiscombination of dispensing actions greatly increases the ability of thedispenser device 10 of the present invention to operate on particulateor granular matter which is recognized as being difficult to move inthis environment.

To describe the overall operation, the propellant 14 is first forced upthrough its dip tube 20 and through the valve 21 and passageway 28 toexpansion chamber 30 when the cap 27 is depressed. The liquid exitingfrom the intermediate orifice 29 immediately expands to form a gaseousvapor at a high pressure and seeks to flow into the nozzle 36, as shownby the flow arrows. The expanding gas travels directly ahead toward therestricted portion 38 where the high velocity, low pressure flow occursdue to Bemoullis principle. However, a portion of the flow is divertedthrough interconnecting transfer passage 45 into the open space abovethe particulate material 12 in the container 11. Since the fluid is agas at high pressure and the particulate material is sufficiently largeto allow the gas to pass through the interstices between the particles,the gas flows down to the lower end of the dip tube 47 and then upwardlytoward the passage 46. This gas fluidizing, that is, surrounding of theparticles in the supply by the gas, and particularly in the regionsurrounding the lower end of the dip tube 47 just as it begins to travelupwardly, enhances the dispensing operation by preventing blockage ofthe flow of the supply. Also, the material is being fluidized as ittravels up the dip tube 47 so that it is in effect, being lifted orcarried upwardly in the stream of gas for dispensing. From the mouth ofthe supply passage 46 connected to the upper end of the dip tube 47, itwill be remembered that the lower pressure generated by the nozzle 36 atthe same time is sucking the fluidized material into the high velocitystream. Thence, the material is dispensed through the orifice 40 forperforming the sandblasting or related operation.

An alternative embodiment is shown in FIG. 2 and will now be described,with the like elements being given the same reference numerals plus asuffix and with additional elements being identified by additionalreference numerals. The container 11a is formed in two sections, anupper section 48 and a lower section 49 with a suitable airtight joint50 being formed therebetween.

With this arrangement, the upper section 48 of the container 110 may beremoved to allow insertion of the propellant tank 13a with a freshcharge and so that additional particulate material 12 may be placed inthe container 1 la. The upper section 48 is formed with annular sealingjoint 51 to maintain the container 11a in a condition to be pressurizedand to thereby cause the particulate material 12 to flow through thedispensing orifice 400 with the maximum force being gained from both thefluidizing and sucking actions.

The venturi nozzle 36a in the dispensing head assembly 31a is modifiedversion of the nozzle 36, shown in FIG. 1. First, the supply passage 46aopens downstream of the restricted portion 380 of the nozzle. Ofimportance is that the side walls of the expanding section 390 leadingto the orifice 400 are set back so as to provide a completely freestream; and the supply passage 46a intersects the nozzle 460 at aposition of negative pressure or vacuum, but downstream of therestricted portion 380.

Because of the space existing between the side walls of section 390 andthe orifice 40a, operation on larger sized particulate material 12 ispossible. This is so since the position of entrance of the particlesinto the high velocity flow stream is less restricted and thus allows agreater volume of particulate material to turn the comer for propulsionthrough the orifice 40a.

The fast moving stream defined by the restriction 38a in effect createsa boundary layer along the side walls of the section 39a to draw thefluid suspended particulate material into the stream. That is, the outerboundary of the stream tends to draw or suck the surrounding fluid andsuspended matter into itself, and accordingly, the vacuum effect at thesupply passage 46a is maintained for efiicient feeding and delivery ofthe fluidized particulate material. The sides of the expanding section39a of the nozzle are not sufiiciently long to permit attachment of theflow stream to one side however; i.e., the fluid at the stepped portionof the orifice 40a will not be trapped sufficiently to provide a captivevacuum to cause the stream to lock-on to one of the side walls.

The lower portion of the nozzle 36a is provided with a projecting lip 55to split the stream issuing from the intermediate orifice 29a to assureadequate supply of fluid for both fluidizing the supply and operation ofthe venturi nozzle 36a (see flow arrows).

Still another embodiment of the Aerosol container device 1 is shown inFIG. 3. In this instance, the venturi nozzle has been designated bynumeral 36b and is formed-as an integral structure with the headassembly 31b, which is pivotally mounted on the top of said container11b by a pivot pin 60. The transfer passage 45b for diverting a portionof the pressurized fluid from the expansion chamber 30b is curved towardthe expansion chamber 301: so as to assure a sufiicient supply of thefluid being scooped and thus supplied to said transfer passage 45b andthe open space above the material in the container 11b. The tubing orbody forming the transfer passage 45b and the supply passage 46b issufficiently flexible (plastic or the like) to permit pivoting of thehead assembly 31b about the pin 60. When the operator thus engages therearwardly extending lever 61, the valve 21b of this embodiment isunseated or opened in response to the downward movement of the rear ofthe assembly 31b toward said valve 21b and discharge of the propellantfluid into the expansion chamber 30b takes place. A convenient handlefor the Aerosol container device 10 is provided by molding a hand holdopening 63, as shown in FIG. 3.

During operation, pressurized fluid is prevented from escaping exceptthrough the supply passage 46b by means of the sealing joint 51. As inthe two previous embodiments, this causes the open space above thematerial to become highly pressurized thereby causing the particulatematerial in the bottom of the container to be saturated with the gas andfluidized, whereby the movement around the lower end and through the diptube 47b and supply passage 46b is greatly enchanced. The fluidizationof the particles is of advantage in the region surrounding the lower endof the dip tube since with the particles being suspended in the gas, ablockage of the tube by jamming of the particles together is preventedSuspension of the particles in the tube 47b and passage 46b alsoprevents blockage, as well as generating positive feeding or liftingforce for the paiticles, as discussed earlier.

The embodiment of FIGS. 4-7 includes a detachable dispensing headassembly, generally designated by the reference numeral 70. Asillustrated in FIGS. 4 and 6, the supply passage 460 of this embodimentof the invention intersects the restriction 38c of the venturi nozzle360 but has a coupling stopper 71 mounted on the lower end thereofrather than a dip tube. The coupling stopper 71 is flanked by twosealing and transfer stoppers 72, 73 each of which has a transferpassage 74, 75 extending axially therethrough and connected to theventuri nozzle 360, as shown in FIG. 4. As in the embodiment of FIG. 1,these passages 74, 75 are thus in communication with the positivepressure of the expansion chamber 30c.

A coupling sleeve 76 provided at the rear of the assembly 70 positionsthe container 80 with respect to upstanding fluid transfer stem 77. Onthis stem 77 is mounted propellant dispensing cap 270, which may beidentical to the cap 27a utilized in the FIG. 2 embodiment. As shown inFIG. 4, the stoppers 7l-73 are centered on a radial arc having a radiusR taken about the center of the coupling sleeve 76 and the stem 77 andare equally spaced from each other.

In FIG. 5 is shown the plan view of the top of a mating container 80operable with the dispensing head assembly 70. A first recessed aperture82 is provided just above the center line of the top 81 to receive thecenter coupling stopper 71 in one mode of operation. The recessedaperture 82 is provided with a centrally located dip tube 83 which ispositioned by an annular disc s as to mate in operation with the feedtube 460.

A second recessed aperture 84 is provided just below the center line ofthe top 81 and is open for direct communication with the space withinthe container 80 (see FIG. 6). Closed recesses 85, 86 flank theapertures 82, 84, respectively, and the recesses and apertures arepositioned along the same radius R, as described with respect to FIG. 4.Furthermore, spacing d between the apertures 82, 84 and spacing d,, d,between the same and the recesses 85, 86 are equal to each other and tothe spacings between the stoppers 71-73 (FIG. 4).

A third recessed aperture 87 is provided at the rear of the top 81 withwhich communication with the propellant tank 13c is made (FIG. 6). Themating coupling sleeve 76 assures easy mounting of the assembly 70 inthe proper position on the tank 130 so that the stem 77 is set tooperate the valve 210 when depressed.

Thus, it can be seen that the assembly 70 of FIG. 4 may be placed inoperating relationship on the container 80 with the stoppers 71-73 andguide sleeve 76 in mating relationship with recessed apertures 82, 84,and 87, respectively, and at least one of the closed recesses 85, 86, aswill now be described.

When the container 80 is to be operated in the upright position, thedispensing head assembly 70 is placed on top of the container 80 so thatthe sleeve 76 mates with the rear aperture 87, the stopper 71 mates withthe aperture 82 with the dip tube 83 (just above the center line in FIG.5) and the stoppers 72, 73, respectively mate with aperture 84, justbelow the center line, and the closed recess 85. Thus, when theexpansion chamber 300 is pressurized through the propellant dispensingcap 270 and the venturi noule 36c is placed in operation, theparticulate material in the container 80 will be withdrawn and dispensedin a manner comparable to the embodiments of FIGS. 1-3. That is, asuction is provided through the passage 46c and the dip tube 83 andpositive fluidizing pressure is provided through passage 74 to aperture84 and thence to the open space above the particulate material 12.

5 jacent a floor or other obstruction. In this mode, the

stopper 71 is first repositioned along the radial arc to cooperate withthe open aperture 84 so that when the particulate material 12 is shiftedby gravity to the top of the container 80 it is in direct communicationwith the feed tube 46c. The stopper 73 is now positioned in engagementwith the aperture 82 having the dip tube 83 so as to provide positivepressure therethrough. Since the dip tube 83 extends above the level ofthe particulate material 12 (see FIG. 6) the same pressurization of theopen space as described above occurs and fluidization for maximumdispensing efficiency takes place; the closed recess 86 properly sealingoff the stopper 72 and thus the passage 74.

When the propellant tank 130 is in the inverted mode, the dip tube 200is now exposed to the vapor phase of the propellant rather than theliquid phase as in the other embodiments (see FIG. 6). This mode ofdispensing of the propellant is suitable where the propellant tank 130is large and efficient heat transfer occurs to prevent the temperatureof the liquid phase from falling below the threshold temperature wherethe vapor pressure is drastically reduced. In certain applications, ithas been found desirable to form a relatively small lateral hole 89 inthe dip tube 20c adjacent the valve 210 so that both liquid and vaporphase propellant are withdrawn in either the inverted or uprightpositions. Preferably, the size of the hold 89 is selected so that thesame liquid/vapor proportion is withdraw from the hole 89 and theopening at the bottom of the dip tube 200 in either selected position.

As best shown in FIGS. 4 and 6, the dispensing head assembly and thecontainer may be conveniently coupled together in either selectedposition by providing latches 90 at the front and rear. The latchesselected may be of the over-center type wherein hooks 91 are provided atthe front and rear of the container 80 (see FIGS. 5 and 6) and an extrahook 92 is provided at the front (see FIG. 5). A U-shaped latch element93 is attached to pivotal lever 94 so as to go into an over-centerposition with respect to the pivot point of lever 94 when the latches 90are secured. There is designed sufficient deformability or flexibilityin the latch element 93 to permit the slight misalignment of the forwardsurfaces of the dispensing head assembly 70 and the container 80 as theformer is latched into either the upright or inverted modes of operationin engagement with either of the forward hooks 91, 92, respectively.

The rear of the expansion chamber 30c of the head assembly 70 is sealedby a removable plug 95. During the assembly of the parts this permitsthe cap 270 to be positioned within said expansion chamber 30c. Thewalls of the expansion chamber 30c are sealed against escape of pressurearound the stem 77 and other points by the requisite close fit of parts,or if necessary, suita ble O-ring structure may be provided.

In order to depress the cap 270 for release of the propellant from thetank 13c, a trigger, generally designated by the reference numeral 96,is positioned in the top of the dispensing head assembly 70. A

reciprocating rod 97 of the trigger 96 extends through the upper wall ofthe chamber 300 and is mated with the top of the cap 27c. Pivotallymounted on the free end of the rod 97 is winged lever 99 having wingsextending outwardly toward the sides of the head assembly 70, as shownin FIG. 7. The double winged lever 99 may be spring biased to a centerposition or freely pivotal, as shown in the drawings. The important factis that the depressing of only one side of the trigger 96 does notresult in activating movement of the rod 97 since the other end of thelever 99 would simply be raised.

Suitable openings 100, 101 are provided in the sides of the headassembly 70 adjacent the trigger 96. These openings 100, 101 provide aconvenient position for insertion of the fingers, when the device 10 isbeing operated in the upright position, or a position for the thumbswhen the container 10d is being operated in the inverted position, asshown in FIG. 6. In the upright position, it will be recognized that thethumbs of the operator are free to engage the adjacent wings of thelever 99 so that the operating rod 97 may be depressed thus releasingthe propellant gas to operate the device 10. In the inverted position,one of the fingers of each hand of the operator naturally falls on theadjacent wing of the lever 99 thereby operating the device 10. Thesafety feature of this arrangement will be recognized since both handsmust be securely in position before the device of the invention can beoperated.

Although all embodiments of the device 10 of the present invention maybe made with any capacity and with any amount of propellant force, theembodiment of FIGS. 4-7 is particularly adapted for high capacity uses.For example, the container may be designed to hold in the neighborhoodof one-half to two cubic feed of particulate material and the propellantmay be charged as high as approximately 200 pounds per square inch. Thisgives the operator the ability to operate on a large area of surface tobe cleaned or abraded with the power normally attributed only tomachines of the non-portable type.

In summary of the foregoing, it can be seen that a highly efficientportable dispenser for particulate material has been provided. Thematerial is propelled from the venturi nozzle 36-360 with thecombination of vacuum lift action and fluidizing and suspension lift ofthe particles by a positive pressure applied into the open space abovethe supply. The venturi nozzle 36-360 and the expansion chambers 30-300are made in different embodiments so as to best suit the particularapplication needed. The detachable dispensing head assembly 70 may besecured to the mating container 80 in two dilTerent positions to adaptthe container 10d for operation in an upright or inverted position. Thetwohand trigger 96 is utilized to assure safety of operation in thisembodiment where extra capacity supply and high-powered propellant maybe utilized.

In this disclosure, there is shown and described only the preferredembodiments of the invention, but, as aforementioned, it is to beunderstood that the invention is capable of various changes ormodifications within the scope of the inventive concept as expressedherein.

lclaim:

1. A portable dispenser for particulate material comprising a containerfor holding a supply of said material, a supply passage extending intosaid container, a source of pressurized propellant fluid, a venturinozzle connected to said source at one end and defining a dispensingorifice at the other end, said supply passage being connected to saidventuri nozzle at a point of vacuum to create a dispensing operation bysucking said material through said supply passage and by projecting thesame at a high velocity and final expansion out said orifice, anexpansion chamber at the upstream end of said venturi nozzle to permitsaid propellant fluid to initially expand prior to entering therestricted portion of said venturi nozzle, a restricted passage upstreamof said expansion chamber and valve means upstream of said passage toregulate the flow of said propellant fluid, said passage terminating ina restricted orifice opening into said chamber ejecting high velocitypropellant fluid into the same for the initial expansion, and transfermeans for interconnecting said pressurized source at said expansionchamber with said container to provide a positive pressure to saidmaterial, said pressure being sufficient to flow through said materialand to thereby fluidize said material in said container and said supplypassage for assisting in the material movement to said nozzle to enhancethe efficiency of the dispensing operation.

2. The portable dispenser of claim 1 wherein said source of pressurizedfluid includes a self-contained tank in said container and a propellantfluid in said tank.

3. The portable dispenser of claim 2 wherein said interconnectingtransfer means includes a restricted passage directly communicatingbetween said expansion chamber and an open space above the supply ofmaterial in said container.

4. The portable dispenser of claim 1 wherein said interconnectingtransfer means includes an open interface between an open space abovethe supply of material in said container and said expansion chamber.

5. The portable dispenser of claim 4 wherein said pressurized sourceincludes an intermediate restricted orifice to provide a defined streamof fluid upstream of and directed toward said venturi nozzle and saidventuri nozzle includes a lip at said one end to intercept said streamof fluid and to split the same between said nozzle and said open space.

6. The portable dispenser of claim 1 wherein said expansion chamber,venturi nozzle and dispensing orifice are formed as an integraldispensing head.

7. The portable dispenser of claim 6 wherein said dispensing head ispivotally mounted on said container at a pivot axis spaced from saidvalve, said valve being connected to said expansion chamber and beingoperable to an open position when depressed, and means for pivoting saidhead toward said valve to operate the same.

8. A portable dispenser for particulate material capable of adaptationfor operation in inverted and upright positions comprising a containerfor holding a supply of said material having a top formed thereon, afirst aperture formed in said top communicating with the space formedabove said material when said container is in the upright position, asecond aperture formed in said top spaced a selected distance from saidfirst aperture,

a dip tube mounted in said second aperture and opening adjacent thebottom of said container, a dispensing head assembly for fitting on saidtop to dispense said material, a source of pressurized fluid andcoupling means on said head assembly adapted to connect said source ofpressurized fluid with said head assembly and to selectively engage saidfirst or second aperture to permit withdrawal of said material from thetop or the bottom of said container in either the inverted or uprightpositions, respectively.

9. The portable dispenser defined in claim 8 wherein said source ofpressurized fluid includes a self-contained tank in said container and apropellant fluid in said tank.

10. The portable dispenser of claim 9 wherein is further provided firstand second sealing stopper means spaced from said coupling means adistance equal to the selected space between said apertures so as tooccupy the one of said apertures not in use by said coupling means fordispensing.

11. The portable dispenser of claim 10 wherein is further provided firstand second transfer passages in communication with said pressurizedsource and extending to said first and second stopper means,respectively, to provide positive pressure to the space formed abovesaid material of said container for assisting in the dispensingoperation.

12. The portable dispenser of claim 11 wherein is further provided firstand second depressions in said top spaced to the outside of saidapertures the selected distance to receive the sealing stopper means notbeing utilized to cooperate with one of said apertures and to block offsaid transfer passages.

13. The portable dispenser of claim 10 wherein is provided a thirdaperture in said top communicating with said pressurized source, secondcoupling means for connecting said source to said dispensing headassembly, said first coupling means and said first and second sealingstopper means being positioned on a radial arc with respect to saidsecond coupling means, whereby the same pressure source may be utilizedfor both modes of operation of said head assembly.

14. The portable dispenser of claim 9 wherein is provided an expansionchamber formed in said head assembly, a propellant dispensing headpositioned in said expansion chamber, said dispensing head having afluid transfer stern, a valve on said propellant tank to release saidpropellant through said transfer stem, a venturi nozzle communicating onone side with said expansion chamber and terminating on the oppositeside in a dispensing orifice, said coupling means being connected tosaid venturi nozzle at a point of vacuum to create a dispensingoperation.

15. The portable dispenser of claim 14 wherein is provided a wingedoperator lever in said head member, rod means engaging the top of saiddispensing head, said winged operator lever being pivotally mounted onsaid operating rod and having lateral wings extending to the oppositesides of said dispensing head assembly, whereby simultaneous engagementby both hands of the operator is required to initiate operation of saiddispenser.

16. The portable dispenser of claim 8 wherein is further provideddeformable latch means to secure said dispensing head assembly and saidcontainer together in an operative condition for use in either of saidpositions.

1. A portable dispenser for particulate material comprising a containerfor holding a supply of said material, a supply passage extending intosaid container, a source of pressurized propellant fluid, a venturinozzle connected to said source at one end and defining a dispensingorifice at the other end, said supply passage being connected to saidventuri nozzle at a point of vacuum to create a dispensing operation bysucking said material through said supply passage and by projecting thesame at a high velocity and final expansion out said orifice, anexpansion chamber at the upstream end of said venturi nozzle to permitsaid propellant fluid to initially expand prior to entering therestricted portion of said venturi nozzle, a restricted passage upstreamof said expansion chamber and valve means upstream of said passage toregulate the flow of said propellant fluid, said passage terminating ina restricted orifice opening into said chamber ejecting high velocitypropellant fluid into the same for the initial expansion, and transfermeans for interconnecting said pressurized source at said expansionchamber with said container to provide a positive pressure to saidmaterial, said pressure being sufficient to flow through said materialand to thereby fluidize said material in said container and said supplypassage for assisting in the material movement to said nozzle to enhancethe efficiency of the dispensing operation.
 2. The portable dispenser ofclaim 1 wherein said source of pressurized fluid includes aself-contained tank in said container and a propellant fluid in saidtank.
 3. The portable dispenser of claim 2 wherein said interconnectingtransfer means includes a restricted passage directly communicatingbetween said expansion chamber and an open space above the supply ofmaterial in said container.
 4. The portable dispenser of claim 1 whereinsaid interconnecting transfer means includes an open interface betweenan open space above the supply of material in said container and saidexpansion chamber.
 5. The portable dispenser of claim 4 wherein saidpressurized source includes an intermediate restricted orifice toprovide a defined stream of fluid upstream of and directed toward saidventuri nozzle and said venturi nozzle includes a lip at said one end tointercept said stream of fluid and to split the same between said nozzleand said open space.
 6. The portable dispenser of claim 1 wherein saidexpansion chamber, venturi nozzle and dispensing orifice are formed asan integral dispensing head.
 7. The portable dispenser of claim 6wherein said dispensing head is pivotally mounted on said container at apivot axis spaced from said valve, said valve being connected to saidexpansion chamber and being operable to an open position when depressed,and means for pivoting said head toward said valve to operate the same.8. A portable dispenser for particulate material capable of adaptationfor operation in inverted and upright positions comprising a containerfor holding a supply of said material having a top formed thereon, afirst aperture formed in said top communicating with the space formedabove said material when said container is in the upright position, asecond aperture formed in said top spaced a selected distance from saidfirst aperture, a dip tube mounted in said second aperture and openingadjacent the bottom of said container, a dispensing head assembly forfitting on said top to dispense said material, a source of pressurizedfluid and coupling means on said head assembly adapted to connect saidsoUrce of pressurized fluid with said head assembly and to selectivelyengage said first or second aperture to permit withdrawal of saidmaterial from the top or the bottom of said container in either theinverted or upright positions, respectively.
 9. The portable dispenserdefined in claim 8 wherein said source of pressurized fluid includes aself-contained tank in said container and a propellant fluid in saidtank.
 10. The portable dispenser of claim 9 wherein is further providedfirst and second sealing stopper means spaced from said coupling means adistance equal to the selected space between said apertures so as tooccupy the one of said apertures not in use by said coupling means fordispensing.
 11. The portable dispenser of claim 10 wherein is furtherprovided first and second transfer passages in communication with saidpressurized source and extending to said first and second stopper means,respectively, to provide positive pressure to the space formed abovesaid material of said container for assisting in the dispensingoperation.
 12. The portable dispenser of claim 11 wherein is furtherprovided first and second depressions in said top spaced to the outsideof said apertures the selected distance to receive the sealing stoppermeans not being utilized to cooperate with one of said apertures and toblock off said transfer passages.
 13. The portable dispenser of claim 10wherein is provided a third aperture in said top communicating with saidpressurized source, second coupling means for connecting said source tosaid dispensing head assembly, said first coupling means and said firstand second sealing stopper means being positioned on a radial arc withrespect to said second coupling means, whereby the same pressure sourcemay be utilized for both modes of operation of said head assembly. 14.The portable dispenser of claim 9 wherein is provided an expansionchamber formed in said head assembly, a propellant dispensing headpositioned in said expansion chamber, said dispensing head having afluid transfer stem, a valve on said propellant tank to release saidpropellant through said transfer stem, a venturi nozzle communicating onone side with said expansion chamber and terminating on the oppositeside in a dispensing orifice, said coupling means being connected tosaid venturi nozzle at a point of vacuum to create a dispensingoperation.
 15. The portable dispenser of claim 14 wherein is provided awinged operator lever in said head member, rod means engaging the top ofsaid dispensing head, said winged operator lever being pivotally mountedon said operating rod and having lateral wings extending to the oppositesides of said dispensing head assembly, whereby simultaneous engagementby both hands of the operator is required to initiate operation of saiddispenser.
 16. The portable dispenser of claim 8 wherein is furtherprovided deformable latch means to secure said dispensing head assemblyand said container together in an operative condition for use in eitherof said positions.